The problem? Trump concluded his tweet with, "Germany is a total mess... GET SMART!"

Unfortunately for Trump, the French capital is not in Germany. Naturally, the hashtag #ParisIsInGermany started trending on Twitter, as Trump's critics took aim at the billionaire for his geographic gaffe.

BREAKING: Angela Merkel surprised to find she has been responsible for Paris all this time. Oh, Trump. You dangerous fool. #ParisisinGermany